JPS6394789A - Pay television transmission/reception - Google Patents

Abstract

PURPOSE:To relieve the economical load of a subscriber by providing a timer switch whose power supply is applied automatically at a set time zone and a timer switch inputting an output of a demodulator at a set time zone only to a decoder decoding enciphered individual information to a receiver to only decode the ciphered individual information with the application of power at the set time zone only. CONSTITUTION:A broadcast program signal is enciphered by a cryptographic device 1 by using a common key sent from a broadcast agent to a reception side at a time zone when a broadcast program is offered ant the result is modulated by a modulator 3 and sent. A switch 7 is connected to the position (a) at a receiver, the broadcast program signal is demodulated by a demodulator 6, received in advance, decoded at a decoder 8 by using the common key stored in a storage device 11 to obtain the broadcast program signal normally. The broadcast agent side connects the timer switch 2 to the position (b) at the time zone, each individual information is enciphered by a cryptographic device 5 and the result is sent through the modulator 3. The timer switch 7 is thrown to the position (b) in the receiver, individual information is connected at a decoder 9 by using a specific key, the corresponding individual information is obtained and the common key is stored in the storage device 11.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a common key necessary for decoding broadcast program signals;
A signal in which individual information, including billing information, information necessary to control the decoder, and individual service information, is encrypted with a key unique to the decoder owned by the subscriber who has entered into a subscription contract with the broadcaster to receive broadcasting services. is transmitted time-sharingly with the broadcast program signal to the pay TV receiving device owned by the subscriber using the same transmission path as the broadcast program signal, and the receiving device decrypts the encrypted individual information using a unique key. The present invention relates to a pay television transmitting/receiving device that decodes a broadcast program signal encrypted with the obtained common key.

[Conventional technology]

FIG. 3 is a block diagram of a conventional example of this type of pay TV transmitting/receiving device, and FIG. 4 is a diagram showing an example of time division of signals transmitted by the transmission (=I device) of FIG.

The broadcast program signal is encrypted by an encoder 1 using a common key, and the individual information is multiplexed with the common key by a multiplexer 4, and then encrypted by an encoder 5 with a unique key to obtain the encrypted individual information. As shown in FIG. 4, the signal is time-division multiplexed with the video signal by the multiplexer 12, modulated by the modulator 3, and transmitted. In the receiving device, the transmitted video signal is demodulated by a demodulator 6, separated into digital individual information, an audio signal, and a broadcast program signal by a multiplexing decoder 17, and then the individual information and the common key are sent to a decoder 9. is decrypted using a unique key and multiplexed 11
The encoder 10 separates the individual information and the common key, and the common key is stored in the storage device 11, after which the broadcast program signal is decoded by the decoder 8 using this common key.

That is, unless the individual information encrypted with the corresponding unique key is transmitted from the broadcaster, this pay television transmitting/receiving device cannot decrypt it with the decoder 9, and therefore cannot obtain the common key. The decoder 8 was unable to obtain a broadcast program signal.

[Problems to be Solved by the Invention] The conventional pay TV transmitting/receiving device described above must always be able to receive broadcast program signals because it is unclear when individual information will be transmitted. First, it has the disadvantage of increasing the financial burden on subscribers.

[Means for solving problems]

The pay TV transmitting/receiving device of the present invention includes a timer switch that automatically turns on the power during a set time period, and inputs the output of the demodulator to a decoder that decodes encrypted individual information only during the set time period. The receiving device has a timer switch for

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a pay television transmitting/receiving apparatus according to the present invention, and FIG. 2 is an η diagram showing the time division side of a signal transmitted by the transmitting apparatus of FIG.

In this embodiment, in place of the multiplexer 13 and multiplex decoder 17 shown in FIG. 3, timer switches 2.7 are installed on the transmitting and receiving sides, respectively, and are set to fall to side b only during a set time period. The receiving side is further provided with a timer switch 12 that is turned on if the power is not turned on during the set time period. power supply, etc.) and the power is always turned on.

Normally, during a time period when a broadcast program is being provided, the broadcast program signal is encrypted by the encoder 1 using a common key that the broadcaster side has previously transmitted to the receiving side, modulated by the modulator 3, and then transmitted.

In the receiving device, the switch 7 is turned to side a, the broadcast program signal is destroyed by the demodulator 6, received in advance, decrypted by the decoder 8 using the common key stored in the storage device 11, and the signal is returned to normal. to get the broadcast program signal. During the set time period (for example, several hours late at night), the broadcaster turns the timer switch 2 to side B, encrypts each individual information with the encoder 5,
It is transmitted in advance through the modulator 3. The receiving device is
The timer switch 7 is turned to the b side, and the decoder 9 decrypts the individual information using the unique key to obtain the corresponding individual information, and stores the common key in the storage device 11.

〔Effect of the invention〕

As explained above, the present invention has the following features:
Normally, by intensively transmitting individual information during times when broadcast programs are not provided, each pay TV receiving device only needs to turn on and decode the encrypted individual information at least during the set time. The power does not need to be turned on except during the set time period, which has the effect of reducing the financial burden on the subscriber. In addition, all set time periods can be used for transmitting individual information, so individual information 1
It is possible to take more information parts per case.

This is particularly effective for pay satellite broadcasting systems that have many subscribers.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram of an embodiment of the pay television transmitting/receiving lit of the present invention, FIG. 2 is a diagram showing an example of time division of signals transmitted by the transmitting device of FIG. FIG. 3 is a block diagram of a conventional device, and FIG. 4 is an example of time division of signals transmitted by the transmitting device of FIG. 1.5... Encryptor, 3... Modulator, 4... Multiplexer, 6... Demodulator, 10... Multiplexing decoder, 11...
. . . A storage device that stores a common key; 2, 7 . . . a timer switch that flips to side b only during a set time period; 12 . . . a timer switch that is connected if the power is not turned on during a set time period.

Claims (1)

[Claims] A common key necessary for decoding a broadcast program signal, billing information,
A broadcast program signal is a signal in which individual information, including information necessary to control the decoder and individual service information, is encrypted with a key unique to the decoder owned by the subscriber who has entered into a subscription contract with the broadcaster to receive broadcasting services. The broadcast program signal is transmitted to the pay TV receiving device owned by the subscriber in a time-sharing manner using the same transmission path as the broadcast program signal, and the receiving device decrypts the encrypted individual information with a unique key. In pay TV transmitting and receiving equipment that decodes broadcast program signals encrypted with a key, there is a timer switch that automatically turns on the power during a set time period, and a timer switch that automatically turns on the power during a set time period, and a timer switch that decodes the output of the demodulator only during the set time period. A pay television transmitting and receiving device characterized in that the receiving device includes a timer switch that is input to a decoder that decodes individual information.